Tool-holder for screw-machines.



PATENTED APR. 28, 1903..

-c. L. GOODRIGH. TOOLHOLDER FOR SCREW MACHINES.

urmonroiw rum) MAY 10, 1902.

2 anus-51mm 1.

N0 MODEL.

PATENTBD APR. 28, 1903-.

No| I O. L. GOODRIOH.

TOOL HOLDER FOR SCREW MACHINES.

APPLIOATION FILED MAY 10, 1902. NO MODEL. 2 SHBETS-BHEET 2.

Clarenae L. 600 612% eh. I

NIT STATES rgENT FFICE.

CLARENCE L. GOODRICH, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE PRATT &XVHITNEY COMPANY, OF HARTFORD, CONNECTICUT, A COR- PORATION OF NEWJERSEY.

TOOL-HOLDER FOR SCREW-MACHINES.

SPECIFICATION forming part of Letters Patent No. 726,674, dated April28, 1903.

a citizen of the United States, residing at Hart-.

ford, in the county of Hartford and State of Connecticut, have inventedcertain new and useful Improvements in Tool-Holders for Screw-Machines,of which the following is a ing part of the screw-machine and capable ofspecification.

My invention relates to screw-machines, l0 and more especially to thatclass of said machines which have an intermittiugly-actuated turret orcarrier in sockets of which the tools or their supports are placed.

Mainly the object of my invention is to so improve a machine of theclass described that its defects will be obviated and atool-holderworking positively and accurately at all times will be produced. I I

A further object of the invention is the provision of improved devicesfor limiting the threading operation, and thus determining the length ofthread to be out. I

A further object of the invention is the provision, in a tool-holder, ofa stationary head having a tubular shank, rods or bolts projecting fromsaid head, a plate having a sliding movement limited by stops on therods in a forward direction, a second head in which the threading-toolis mounted, said head having a stem passing through a perforation in theplate, and a spring bearing against said plate. In the accompanyingdrawings, Figure 1 is a side elevation of a portion of a screw-machinewith my improved tool-holder applied 35 thereto. Fig. 2 is a perspectiveview of said tool-holder. Fig. 3 is'a view of the face of the movablemember of. saidv tool-holder with a screw-cutting die'shown'therein.Fig. 4 is a longitudinal vertical'section of the tool-holder 0 withcertain parts shown in elevation. Fig. 5 is an end view of the fixedmember of the too1-holder,showing astop carried in the stem.

Application filed May 10, 1902f Serial No. 166,669 (No model.)

Referring to the drawings, the numeral 5 designates the frame of ascrew-machine, and

=thenumeral 6 pulleys mounted upon a spindle 7, which is designed tocarry the stock- -chuck and to impart rotaryrnotion thereto when .poweris applied to the spindle.

In a turret 8, carried by a slide 8, form-v longitudinal movement eitherby hand or antomatically, as desired, upon the framework thereof, ismounted my improved tool-holder, designated in a general way by 9 andcomprising a fixed member 10, having a tubular shank 12, which issecured in any desired manner in a socket of the turret, said shankbeing internally threaded at 13, as illustrated in Fig.4, and carryingan adjustable split plug or stop 14, subserving a purpose hereinafterdescribed.

Mounted for reciprocative movement in the bore of the shank 12 is thestem 15 of the movable member of my improved tool-holder, which stemprojects from a head 16, provided with a recess 16 for the reception ofa screwthreading'die 17, held therein by a set-screw 18, fitted into athreaded bore 19 and bearing at its inner end against said die. Thishead 16 is also provided with perforations 20, into each of which opensa slot 20 for the reception of bolts or projections 22 and stop pins orlugs 23, carried by said bolts, said bolts 22 passing through theperforations 20 and the stop-pins 23 through the slots 20 and the rearends of said bolts being threaded into the head of the fixed member 10.

Slidinglyrmounted upon thestem 15 is a plate 24, through perforations inwhich the bolts 22 pass, and bearing between said plate and a collar 25,secured to the stem 15, is a spring 26. The fixed member 10 is recessedgat 27 to receive said collar and spring when the movable member is movedto the right in Fig. 4, and the plate 2t-is preferably provided with adepression 24 to accommodate the end convolution of the spring 26. 5

As best illustrated in Figs. 7 and ,8, the head 16 of the movable memberis recessed at 28 for the reception of the heads of spring pressedlatches 29, the stems 29 of said latches carrying coil-springs 30, whichnormo mally tend to force the latches outward or to the right in Fig. 7.Upon their opposite ends the stems of the latches carry stop-pins 31,which engage the end walls of slots 32 in the head, as shown in Fig. 8,and thereby limit the outward movement of said latches.

The operation of this improved tool-holder is as follows: At thecommencement of a thread-forming operation the tool-holder is in theposition illustrated in Fig. 1, where the turrethas been advanced, andthe rapidlyrevolving stock is therefore in engagement with thescrew-threading die 17 or other tool employed carried in the recess 16,and it is obvious that when this is done the movable member 16, carryingsuch screw-threading tool, will be held against rotative movement by thebolts 22, which have then entered the perforations 20, and that it willbe drawn forward or to the left in Figs. 1 and 4 until it reaches theposition shown in Fig. 4, when the plate 24 will come into contact withthe stop-pins 23 of the bolts 22, after which any further movement ofthe member 16 in a forward direction will be made against the tension ofthe spring 26, this further movement, which now takes place, serving toWithdraw the bolts 22 from the perforations 20 and causing thethread-forming operation to cease, as the member 16 will now rotate idlywith the stock. As shown in Fig. 2, the fixed and movable members havenot been separated from one another far enough to cause the plate 24 tocomeinto contact with the stop-pins 23; but when this happens said platewill be forced from the position shown in said Fig. 2 to thatillustrated in Fig. 4, thereby permitting the latches 29 to be forcedoutward by the springs 30, as shown in Figs. 7 and 8, until thestop-pins 31 come into contact, as hereinbefore described, with thebottoms of the slots 32. As the movable member continues to revolve idlywith the now threaded stock the projecting latches 2.) strike againstthe bolts 22, said bolts riding over the inclined end faces 29 of thelatch-heads as long as said movable member continues to rotate in aforward direction. The direction of rotation of the stock-holding chuckis now reversed, and the bolts 22 will therefore engage the sides of thelatch-heads, which will hold the movable member against further rotationin a reverse direction and will cause said member to be forced towardthe fixed member by the threaded work as it withdraws from the tool, andthe bolts 22 will new again enter the perforations 20 until the movableand fixed members come into contact preparatory to repeating thethreading operation. When it is desired to vary the length of thread tobe cut, the split plug or stop 14 is screwed into the shank 12 until itassumes any desired position longitudinally thereof, thereby acting as astop for the stem of the movable member to abut against and determiningthe point at which said movable member shall again begin thethread-forming operation, and consequently the length of thread to beout upon the stock.

In devices of this character it has been found that when the turret isrotated preparatory to beginning the thread-forming operation theinertia of the movable member is apt to cause it to be thrown away fromthe fixed member, which is objectionable, for if when that is done thebolts 22 should be thrown out of alinement with the perforations 20 suchalinement would have to be restored by hand before the formation of thethread could be continued, and to overcome this objection the plate 24,collar 25, and spring 26 are provided, said spring being of sufficienttension to resist any tendency of the movable member to be thrown beyondthe ends of the bolts 22 under the action of centrifugal force.

Any means for reciprocating and intermittingly rotating the turret,either manually or automatically, may be employed; but as such meansconstitute no part of my invention they are not illustrated.

While a screw-cutting die is shown mounted in the movable member of thetool-holder, my invention is not limited thereto, for a tap or otherscrew-cutting tool may besubstituted therefor, if desired.

My invention is not limited to the precise construction illustrated, formany changes may be made without departure therefrom, nor is it limitedto use with any particular kind of machine.

Having thus described myinvention, what I claim is- 1. In a tool-holder,the combination, with a member having a tubular shank, of a secondmember having a stem inserted in the bore of said shank; means forclutching said members; a turret on which the member having a shank iscarried; a yielding plate carried by the movable member; and meanswhereby said plate is caused to resist the movement of said movablemember when the turret is rotated, to thereby prevent disconnection ofthe means for clutching said members.

2. The combination, withatool-holder comprising two members, one ofwhich is reciprocative and rotative relatively to the other, said memberhaving perforations, of yielding stops carried by said member; boltscarried by the other member and adapted to enter the perforations andalso to en gage said stops; a plate fitted upon the bolts; lugs carriedby said bolts and fitting keyways in the movable member; and a springcarried by one member and bearing against the plate.

3. The combination,with a tool-holder comprising two members, one ofsaid members having a socket, of a stem carried by the other member andfitting in said socket; a series of projections carried by one memberand adapted to fit in a corresponding series of recesses in the othermember; a yielding stop adapted to be engaged by one of the projections;a de- IIO vice slidably mounted upon said stem; acollar upon said stem;and a spring between said collar and said deviceand normally holding thedevice and the other of said members in contact.

4. In a tool-holder, the combination, with a fixed member and a movablemember, of projections carried by one of said members,

the other member having perforations or recesses for-the reception ofsaid projections; a stem on one of the members; stops carried by saidprojections and located adjacent to the ends thereof; and aspring-controlled plate carried by said stem and adapted to be engagedby said stops before the projections are withdrawn from the recesses 'orperforations, upon the movement of the movable member away from thefixed member.

5. In a tool-holder, the combination, with a fixed member, of a movablemember, one of said members having projections and the otherperforations to receive the projections; a yielding plate carried by themember having perforations; stops carried by the projections; andyielding stops on one of the members withwhich the projections areadapted to engage.

6. In a tool-holder, the combination, with a fixed member, of a movablemember; a series of projections carried by one member and adapted toengage the other member; a springcontroileddevice carried by one of thesaid members; and stops upon the other member arranged to. engage thespring-controlled device, said stops serving to limit the outwardmovement of the movable member.

7. The combination, with a tool-holder,com prising fixed and movablemembers, of projections carried by one of said members; and

adapted to enter recesses formed in the other member; a split stopthreaded into a bore of the fixed member; and astem on the movablemember slidably mounted in said bore, and adapted to engage said stop.

8. In a tool-holder, the combination, with a fixed member, of a movablemember, one of said members having a stem slidably mounted in a bore ofthe other member; projections carried by one of said members and adaptedto enter recesses in the other memher; and a stop threaded into saidbore, and serving to limit the movement of said movable member.

9. The combination, with a turret, of a head having a tubular shank;rods projecting from said head; a tool-carrying head having perforationsto receive the rods, and provided with a stem entering the tubularshank; a plate carried'by the stem and perforated to receive the rods;lugs on the rods arranged to engage the plate for limiting the outwardmovement of the tool-carrying head; and a spring carried by the stem andbearing against said plate.

10. The combination, with a head having a bore, of a second head havinga shank inserted in said bore and slidable therein; means for clutchingthe heads; a plate movable with relation to the shank; a spring bearingagainst said plate; and means arranged to contact with the plate forarresting outward movement of the movable head.

In testimony whereof I aflix my signature in presence of two witnesses.

CLARENCE L. GOODRIOH.

Witnesses:

WILLIAM H. MILLER, DEAN E. BELOHER.

